Certain Physico-Chemical Characteristics of Muscle Globulin

The significance of the protein constituents of muscle for the contractile process has long been recognized. The instability of these bodies, however, has rendered difficult their characterization. Danilewsky1 described the extraction of muscle protein with sal ammoniac in 1881. The older method of expression, despite rigid precautions, often led to “denaturation” or “clotting of muscle plasma.” The properties of muscle globulin, as of other globulins, are altered both by too low salinity and by too high acidity.2 Howe3 has employed phosphate buffers as solvents to overcome these difficulties. In the present investigation an ammonium chloride solution, rendered alkaline by excess of ammonia, was used as solvent and yielded solutions of muscle protein which, for several months, retained solubility in neutral salt solutions.A globulin-like fraction of ox muscle protein was studied, which presumably corresponded to the “myosin” of von Furth4 and the “paramyosinogen” of Halliburton.5 The method of preparation...